• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.1
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• pp.1-11
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• 2002

This study was conducted to reveal the effects of local climatic conditions on the early growth of Korean white pine progeny test stands. For this, stand variables such as mean DBH, mean height, basal area per hectare, and volume per hectare by stand age and locality were first measured and summarized for each stand. Based on these statistics, annual increments for 10 years from stand age 10 to 20 were calculated for each of stand variables. The effects of local climatic conditions as one of environmental factors on the growth were then analyzed by both a topoclimatological method and a spatial statistical technique. From yearly climatic estimates,30 climatic indices which affect the tree growth were computed for each of the progeny test stand. The annual increments were then correlated with and regressed on the climatic indices to examine effects of local climatic conditions on the growth. Gapyung area provided the best conditions for the early growth of Korean white pine and Kwangju area ranked second. On the other hand, the growth pattern in Youngdong ranked last overall as expected. It is also found that the local growth patterns of Korean white pine in juvenile stage were affected by typical weather conditions. The conditions such as low temperature and high relative humidity provide favor environment for the early growth of Korean white pine. Especially, it was concluded that the low temperature is a main factor influencing the early growth of Korean white pine based on the results of correlation analysis and regression equations developed far the prediction of annual increments of stand variables.

• Journal of Korean society of Dental Hygiene
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• v.12 no.1
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• pp.123-133
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• 2012

Objectives : This study was performed to understand smoking condition and to investigate the relations among knowledge regarding smoking and oral hygiene, awareness of anti-smoking policy, and self-esteem, to provide fundamental basis, developing programs for smoking prevention and anti-smoking. Methods : From September 7, 2010 to September 16, 2010, questionaire survey was conducted for 566 female university students studying dental hygienics at a local district in Jeollanam-do. Collected data was analyzed by Chi-square test, t-test, one way ANOVA, Scheffe multiple range test, Perason's correlation test, and stepwise multiple regression test. Results : 1. Smoking condition of study subjects on general characteristics showed 17.1%, where 14.0% of previous smoking history, and 68.9% of currently nonsmoker. 2. Analysis on the knowledge related to smoking and oral hygiene, awareness of anti-smoking policy, and self esteem on the general characteristics of study subjects have shown better awareness of anti-smoking policy in non-alcoholics. Significant difference was found in knowledge about smoking and awareness of anti-smoking policy according to current resident status, but no difference found in self-esteem. Higher academic grade was related to higher awareness of anti-smoking policy and better ics. aalcell. Better health, but no diffeoral hygiene were related to better awareness of anti-smoking policy, and bewhich were statistically significant. Favorable interpersonal self-estehip was related to better awareness of anti-smoking policy. 3. Analysis on knowledge regarding smoking related health and oral hygiene, awareness of anti-smoking policy, and self-esteem showed higher level of anti-smoking knowledge in non-smoking group(60.44) compared to currently smoking group or group with previous history of smoking, and better awareness of anti-smoking policy in non-smoking group(53.54) than other groups, which was statistically significant. 4. Correlation analysis among smoking related knowledge, awareness of anti-smoking policy, and self-esteem has found relatively high correlation between smoking related knowledge and awareness of anti-smoking policy, which was statistically significant(r=0.481, p<0.001). 5. Among factors influencing awareness of anti-smoking policy, higher level of smoking related knowledge and satisfaction to specialty was related to higher awareness of anti-smoking policy which was lower in current smoker than past smoker, and higher academic grade was related to higher awareness of anti-smoking policy. Conclusions : Following results emphasize the need to establish a novel curriculum by which effective programs for smoking prevention and education of anti-smoking specialist could be provided as well as promoting coaching anti-smoking activity.

• Journal of Korean society of Dental Hygiene
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• v.15 no.1
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• pp.81-89
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• 2015

Objectives: The purpose of the study is to investigate the effect of values on major satisfaction in dental hygiene students. Methods: The subjects were 214 dental hygiene students in Seoul and Gyeonggi-do who filled out the self-reported questionnaire after receiving informed consents from January 20 to February 15, 2014. Except incomplete answers, 187 data were analyzed using PASW Statistics 18.0 for Scheffe post hoc test, Pearson correlation coefficient, hierarchical regression analysis, independent sample t-test, and one-way ANOVA. The questionnaire consisted of general characteristics of the subjects and values. General characteristics consisted of gender, age, grade, school record, major choice motivation, and the influencing person to choose the major. The instrument for values was modified from Shin based on MILOV(Multi-Item Measures Of Values) and two professors of dental hygiene verified the validity of the instrument. Instrument for values consisted of 7 questions of values for self-respect, 6 questions of relation oriented values, 5 questions of emotion oriented values, and 5 questions of values for others measured by Likert 5 scale. Cronbach's alpha was 0.769 in the study. The instrument for major satisfaction was modified from Na based on Program Evaluation Survey of Illinois University and two professors of dental hygiene verified the validity of the instrument. Major satisfaction consisted of 7 questions of general satisfaction, 5 questions of consciousness satisfaction, 5 questions of curriculum satisfaction and 3 questions of relation satisfaction measured by Likert 5 scale and Cronbach's alpha was 0.887 in the study. Results: Values of self-respect, relationship orientation and grade had significant influence on general satisfaction, while values of self-respect, relationship orientation and gender had significant influence on consciousness satisfaction. Values of relationship orientation, grade and school record had significant influence on curriculum satisfaction. Grade showed significant influence on relationship satisfaction. Conclusions: Values of self-respect and relationship orientation are the most important factors in dental hygiene students. The guidance for professional career and major satisfaction can be accomplished through the values of self-respect and relationship orientation.

• Journal of Korean society of Dental Hygiene
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• v.15 no.1
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• pp.63-71
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• 2015

Objectives: The purpose of the study is to investigate the relationship between bone mineral density and remaining teeth in Korean adults. Methods: Using National Health and Nutrition Examination Survey(KNHANES) 5th Year 1(2010), 1,985 adults over 50 years old having bone mineral density test were selected. Male adults were 883, and female adults were 1,102. The raw data consisted of general characteristics of the subjects, bone density data, and oral examination data. The questionnaire consisted of general health survey, laboratory examination study, and nutrition study. Data were analyzed using SPSS 18.0 program for multiple regression analysis, ANOVA, t-test. The variables included general characteristics of the subjects, health behavior, diet habit, and oral health behavior. General characteristics consisted of gender, age, residence area, education level, marital status, monthly income, and vocation. Health behavior consisted of smoking, alcohol drinking, body mass index(BMI), physical activity, and mental health. Diet habit consisted of frequency of meal, milk, coffee, and calcium ingestion. Oral health behavior consisted of frequency of tooth brushing, use of oral health care devices, and oral examination. Systemic diseases were measured by the questionnaire for hypertension, diabetes mellitus, and hyperlipidemia. Bone density was measured in T-score of femoral bone, neck of femur, and lumbar vertebrae. Bone density was classified into normal($T-score{\geq}-1.0$), osteopenia(-2.5 < T-score < -1.0), and osteoporosis ($T-score{\leq}-2.5$). The remaining teeth were measured by the differences between normal teeth and missing teeth. Results: Smoking and age are the most influencing factors on the number of remaining teeth and bone density(p<0.01)(p<0.05). Those who had higher bone density, younger age, and nonsmoker significantly had more remaining teeth. Those who were men, diabetic, lowly educated women, and low birth weighted persons tended to have less number of teeth(p<0.01). Conclusions: The study suggested that there were significant differences between men and women according to the oral health management behavior and systemic disease control. Proper management of the oral health and good quality of bone mineral density can reserve the remaining teeth through the whole life.

• Explosives and Blasting
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• v.17 no.4
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• pp.67-88
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• 1999

Ground settlements induced by tunnel excavation cause the foundations of the neighboring superstructures to deform. An expert system called NESASS was developed to analyze the structural safety of such superstructures. NESASS predicts the trend of ground settlements to be resulted from tunnel excavation and carries out a safety analysis for superstructures on the basis of the predicted ground settlements. Using neural network techniques, NESASS learns a data base consisting of the measured ground settlements collected from numerous actual fields and infers a settlement trend at the field of interest. NESASS calculates the magnitudes of angular distortion, deflection ratio, and differential settlement of the structure and, in turn, determines the safety of the structure. In addition, NESASS predicts the patterns of cracks to be formed on the structure using Dulacskas model for crack evaluation. In this study, the ground settlements measured from the Seoul subway construction sites were collected and sorted with respect to the major factors influencing ground settlement. Subsequently, a database of ground settlement due to tunnel excavation was built. A parametric study was performed to verify the reliability of the proposed neural network structure. A comparison of the ground settlement trends predicted by NESASS with the measured ones indicates that NESASS leads to reasonable predictions. An examples is presented in this paper where NESASS is used to evaluate the safety of a structure subject to deformation due to tunnel excavation near to the structure.

• Journal of Science Education
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• v.34 no.1
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• pp.1-11
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• 2010

This study analyzes the factors influencing academic achievement on mathematic and scientific subject and its change in Korean youth by using a sample from KYPS(Korea Youth Panel Survey) data. The results are as follows: First, academic achievement on mathematic and scientific subject of Korean youth shows quadratic curve that their interrelationship between intercept and slope of academic achievement are negative which is statistically significant. Second, analysis of Latent Growth Models shows that parents, teacher, peer group, self esteem, income of family, high school tracks are found to be a statistically significant factor on mathematic. And scientific subject is affected by parents, teacher, peer group, self esteem, income of family, high school tracks. Also, Interesting finding is that father's job is not significant to dependent variables. These findings show that academic achievement on mathematic and scientific subject of the Korean youth are the quadratic curve and influenced by parents, teacher, peer group, self esteem, income of family, high school tracks. To improve youth's mathematic and scientific, Korea educational fields and educators should have policy to care youth's relationship with parents, teachers and self esteem.

• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.474-484
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• 2005

Biological treatment is a promising alternative to conventional air pollution control methods. Bioreactors for air pollution control have found most of their success in the treatment of dilute and high flow waste air streams containing volatile organic compounds and odor compounds. They offer several advantages over traditional technologies such as incineration or adsorption. These include lower treatment costs, absence of formation of secondary pollutants, no spent chemicals, low energy demand and low temperature treatment. The most widely used bioreactor for air pollution control is biofilter, but it has several limitations. In the past years major progress has been accomplished in the development of vapor phase bioreactor, in particular biotrickling filters. Biotrickling filters are more complex than biofilters, but are usually more effective, especially for the treatment of compounds which are difficult to degrade or compounds that generate acidic by-products. While the level of understanding of biotrickling filtration process for VOCs still remains limited, the evident success of biotreatment of VOC in air stimulated the pursue of acitve research. This paper presents fundamental and theoretical/practical aspect of air pollution control in biotrickling filter. Special emphasis is given to the operating parameters and the factors influencing performance for air pollution control in biotrickling filter.

• Journal of Bio-Environment Control
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• v.12 no.3
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• pp.107-113
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• 2003

This study was carried out to improve the performance of pre-developed heat recovery devices attached to exhaust-gas flue connected to combustion chamber of greenhouse heating system. Four different units were compared in the aspect of heat recovery performance; A-, B-, and C-types are exactly the same with the old ones reported in previous studies. D-type newly developed in this experiment is mainly different with the old ones in its heat exchange area and tube thickness. But airflow direction(U-turn) and pipe arrangement are similar with previous three types. The results are summarized as follows; 1. System performances in the aspect of heat recovery efficiency were estimated as 42.2% for A-type, 40.6% for B-type, 54.4% for C-type, and 69.2% for D-type. 2. There was not significant improvement of heat recovering efficiency between two different airflow directions inside the heat exchange system. But considering current technical conditions, straight air flow pattern has more advantage than hair-pin How pattern (U-turn f1ow). 3. The main factors influencing on heat recovery efficiency were presumably verified to be the total area of heat exchange surface, the thickness of ail-flow pipes, and the convective heat transfer coefficient influenced by airflow velocity under the conditions of allowable pipe durability and safety. 4. Desirable blower capacity for each type of heat recovery units were significantly different to each other. Therefore, the optimum airflow capacity should be determined by considering in economic aspect of electricity required together with the optimum heat recovery performance of given heat recovery systems.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.1
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• pp.40-48
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• 2017

RC flat plates may be governed by a serviceability as well as a strength condition, and a construction sequence and its impact on the distributions of gravity loads among slabs tied by shores are decisive factors influencing short and long term behaviors of flat plate. Over-loading and tensile cracking in early-aged slabs significantly increase the deflection of a flat plate system under construction, and a reshoring work may be helpful in reducing slab deflections by controlling the vertical distributions of loads in a multi-shored flat plate system. In this study, a effect of reshoring works on short and long term deflections of flat plate systems are analyzed. The slab construction loads with various reshoring schemes and slab design and construction conditions are defined by a simplified method, and the practical calculation of slab deflections with considering construction sequences and concrete cracking and long term effects is applied. From parametric studies, the reshoring works are verified to reduce slab deflections, and the optimized conditions for the reshoring works and slab design and constructions are discussed.

• Journal of Gifted/Talented Education
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• v.22 no.3
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• pp.757-777
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• 2012

Peer relationships in young students' communities are one of the important factors influencing the cognitive and affective domains of learning. Moreover, students who join the special program for gifted students possess differential peer relationships from the students in general classes. This study aims to explore the differences of 5th grade five science-gifted students' peer relationships between students in special classes for gifted students and general classes. Five students in the special program for gifted students, managed by the Office of Education in a southern city, participated in this study. Social network analyses were utilized to explore participants' peer relationships; the students' homeroom teacher was interviewed to explore the contextual and in-depth characteristics of gifted students' peer relationships. The results illustrated four cases of peer relationships: (1) smart loner (2) my study mate (3) I'm the best in my class, and (4) a good friend anywhere. This study identified that the gifted students possessed diverse peer relationships in both the special program and general classroom. In addition, this study suggests that the program for gifted students needs to be specially designed based on the gifted students' peer relationship.